The objective of this research was to study the relationship between land occupation
and water quality in the Rumiyacu and Mishquiyacu micro-watersheds, district and province of Moyobamba, department of San Martín. Water samples were taken at six points in the riverbed: two in the upper basin, two in the middle basin and two in the lower basin and analyzed the physical, chemical and bacteriological parameters. Water temperature and pH were measured in the riverbed; nitrate, phosphates, faecal coliforms, turbidity, total solids, dissolved oxygen, biochemical oxygen demand were evaluated in the laboratory to be compared with a water quality index according to the standards (ICA). They were found to be within the "regular" category, with turbidity and fecal coliforms negatively influencing ICA behavior. The results were contrasted with national environmental quality standards for water (ECA). The actions that generate the deterioration of the water quality of the micro- watersheds and cause potential impacts are the occupation of the territory by 120 families, where 35 live permanently; the land use change in 469.35 hectares, which represents 60.06% of the total area; the cultivation of coffee, which is the main economic activity with 210.24 hectares. Land use change generates pollution, especially at harvest times, as well as deforestation and forest damage in an area of 60.06%, which leads to lossa lot of biodiversity, causing degradation, pollution, reduced soil fertility, decrease in water regime and water pollution. The Population Pollution Index (ICP) is more significant in the upper basin followed by the lower basin, and the lowest index is in the average riverbed because in this area is the largest primary forest territory, 18.84% of the area of the Mishquiyacu micro watershed. Rumiyacu and Mishquiyacu micro-watersheds have been shown to show significant deterioration of water quality, that land use by 657 people and current land use
has a negative impact; In addition, primary forest positively influences water quality.